SELECT continent
,sum(pop)
FROM gapminder.gapminder
WHERE year = 2007
GROUP BY continent;
library(DBI)
# 利用 `dbConnect()` 建立連線
con <- dbConnect(RMySQL::MySQL(),
dbname = "gapminder",
host = "rsqltrain.ced04jhfjfgi.ap-northeast-1.rds.amazonaws.com",
port = 3306,
user = "trainstudent",
password = "csietrain")gapminder_df <- dbReadTable(con, "gapminder")
dbDisconnect(con)library(dplyr)
library(ggplot2)
plot_df <- gapminder_df %>%
filter(year == 2007) %>%
group_by(continent) %>%
summarise(ttl_pop = sum(as.numeric(pop))) %>%
arrange(ttl_pop)
plot_df$continent <- factor(plot_df$continent, levels = plot_df$continent)
bar_plot <- ggplot(plot_df, aes(x = continent, y = ttl_pop, fill = continent)) +
geom_bar(stat = "identity", alpha = 0.5) +
xlab("") +
ylab("") +
theme_minimal() +
coord_flip() +
ggtitle("Population across different continents")